This invention relates in general to devices to prevent side roll-over of dump trucks during dumping operations and, more specifically, to measure side tilt, display the tilt and sound an alarm and/or automatically stop elevation of the trailer in the event of a dangerous tilt.
A variety of dump trucks have been developed and are in use for hauling material such as sand, gravel, asphalt, trash and the like in a truck or trailer mounted bin and dumping the material by elevating the front of the bin and allowing the material to slide out through a back door or gate very long bins mounted on trailers are used to carry a large amount of heavy material. When the front end of the bin is raised very high to assure that the material will slide out, a very long moment arm is created. If the vehicle is tilted even very slightly to the side, the entire vehicle is likely to roll over and be severely damaged and may injure the operator. With very long trailer mounted dump bins, with an eight foot wheelbase, it is dangerous to have one side even seven inches or so higher or lower than the other side.
It is difficult for the driver to "feel" the slight degree of tilt that can be dangerous with very long dump bins, in particular with tractor-trailer combinations where the tractor might be on level ground while the trailer is on sloping ground. Various spirit levels and the like have been used in the truck cab to indicate the degree of tilt. These often do not have sufficient accuracy to accurately show the small degree of tilt that may be dangerous with very long dump bins. Again, the angle of tilt of a tractor may be much different than the tilt of a trailer in a tractor-trailer combination. A level indicator may be included on the trailer, but this will require that the driver leave the tractor, check the level and return to the cab to begin the dumping operation. This check may be overlooked where rapid transportation and dumping turn-around times are necessary. Further, most levels lack the required accuracy.
Thus, there is a continuing need for improved apparatus for accurately measuring the degree of side tilt of a dump truck or trailer, indicating the actual tilt, preferably by the relative height of one side compared to the other, providing a clear and accurate display of the relative tilt to an operator in a tractor cab or near a trailer and to sound an alarm and/or automatically stop the elevation of the dump bin front end if a safe tilt is exceeded.